1. Field of the Invention
The present invention relates to an improved more reliable light emitting wheel hub for a light emitting wheel and method for making the same. The light emitting wheel is useful for skate board, roller skate, in-line roller skate, wheel chair and like apparatus. The invention additionally provides for greater efficiency in mass production, especially in automated mass production of a light emitting wheel.
2. Description of the Related Art
There have been a number of attempts to produce a satisfactory light emitting wheel that could be mass produced. In particular, the armature assembly or yoke of the compact generator have been positioned or embedded in the wheel hub of the wheel that rotates around a permanent magnet positioned on the wheel axle of the type shown in U.S. Pat. No. 6,398,395.
The patent discloses a compact generator and light emitting wheel. The coil bobbin or spool of the armature assembly of the compact generator is shown in FIG. 2. Each lead wire extends from the coil through a respective guide element 145, which is advantageously a tube. The lead wire is secured at the narrow portion 146 prior to connecting to the light emitting device. The coil bobbin is then combined with an armature cover bearing armature arms to form an armature assembly. A polymer or resin is injection molded around the armature assembly and fixedly incorporated or embedded to form a wheel hub. A conductive plate or printed circuit board bearing light emitting device such as a LED (light emitting diode) is connected to the wheel hub to form a wheel hub assembly and subsequently a wheel tire using resin or polymer such as polyurethane is molded around the wheel hub.
Korea Patent Application 10-2000-0086367 published Jul. 12, 2002 shows an improvement on the armature assembly of type shown in U.S. Pat. No. 6,398,395 and is shown in FIG. 3. In order to provide a better connection between the lead wires of the coil bobbin, and the light emitting device, lead wire 142b is guided from the coil on grooves in block extension 142a and connected to conductive pin 142d which is subsequently connected to the light emitting device. The lead wires are manually wrapped around respective conductive pins.
Korea Patent Application 10-2006-0027308, published Aug. 22, 2007 improved the prior art armature assembly shown in FIG. 2, by simplifying the connection of the lead wires and thereby the manufacturing process through a modification of the prior armature assembly and is shown in FIG. 4. Lead wires 202 and 206 from coil bobbin 207 protrude outside armature cover 200 and 201 and are manually connected to armature cover extensions 203 and 205. Armature covers 200 and 201 bear armature arms 204. Armature extensions connect with a light emitting device, a conductive plate or printed circuit board bearing a LED. This design was prone to frequent lead wire separation or breakage and electrical failure at the contact point with the armature cover extensions during injection molding of the wheel hub.
Korea Patent Application 10-2006-0058747, published Jun. 6, 2006 also discloses an improvement of the over the prior art armature assembly shown in FIG. 2. As seen in FIG. 5, coil bobbin 210 has extensions 212 and 217 where upon lead wires 214 and 215 from the wire coil is secured to prior to injection molding of the wheel hub and manually connecting the lead wires to armature cover extensions 208 and 209 of armature covers 211 and 216.
The above prior art patents employ thin fragile lead wires that are drawn out and away from the coil bobbin outside the armature cover and manually connected to the light emitting device as in the aforementioned US patent or to an extension of the armature cover as in the aforementioned Korea Patent Applications. Wheels incorporating compact generators of US patent and Korea Patent Application were prone to circuit failure in the manufacturing process because of frequent breakage of the lead wire from the coil bobbin during manual manipulation to connect the thin lead wire to the light emitting device or to the conductive pins.
The Korea Patent Applications had additional problem of the lead wire separating from the conductive pin or from the armature cover extension during high pressure and temperature injection molding of the wheel hub resulting in loss of conductive contact and electrical failure. This problem is exacerbated because the lead wires are not soldered to the conductive pins or armature cover extensions because of the high temperature and pressure of the injection molding process.
The lights of the above prior art wheels were not reliable as the fragile very thin lead wire connecting the conductive pins or posts frequently broke during under stress and shock of hard use or under cold temperatures. This was especially evident when the wheels were used for skates and skate boards.
The introduction of air bubbles in the polymer wheel during the cast molding of the polymer tire onto the prior art wheel hub bearing the armature assembly and light emitting device is another problem that frequently occurred, which reduce quality and production efficiency.